Medical capsule subsystem for precise autonomous localization using odometry

Abstract

Systems and methods of providing an ingestible medical capsule (a capsule) are described. In some implementations, the capsule is configured to measure a distance traveled (by the capsule) through a gastrointestinal tract of a subject. In some cases, the capsule includes an anchor configured to associate with a portion of a gastrointestinal tract of the subject. In some iterations, the capsule includes a capsule body coupled to the anchor via a strand. In some cases, the capsule body is configured to travel a distance away from the anchor along the gastrointestinal tract of the subject and to measure the distance using the strand as a reference. Additional implementations are described.

What is claimed is: 
     
         1 . An ingestible medical capsule configured to measure a distance traveled by the ingestible medical capsule through a gastrointestinal tract of a subject, the ingestible medical capsule comprising:
 an anchor configured to associate with a fixed anatomical feature of the subject; and   a capsule body coupled to the anchor via a strand, the capsule body being configured to travel a distance away from the anchor along the gastrointestinal tract of the subject and to measure the distance using the strand as a reference.   
     
     
         2 . The ingestible medical capsule of  claim 1 , wherein the ingestible medical capsule is configured to perform an action at a certain point along the gastrointestinal tract, wherein the action includes at least one of: administering a medication; collecting a sample; capturing information; and transmitting data. 
     
     
         3 . The ingestible medical capsule of  claim 2 , wherein the ingestible medical capsule is configured to perform the action in response to the capsule body traveling a certain distance away from the anchor. 
     
     
         4 . The ingestible medical capsule of  claim 1 , wherein the anchor is initially associated with the capsule body, and wherein the anchor is configured to dissociate from the capsule body after the subject ingests the ingestible medical capsule. 
     
     
         5 . The ingestible medical capsule of  claim 4 , further comprising an enteric coating configured to dissolve after the subject ingests the ingestible medical capsule to trigger a dissociation of the anchor from the capsule body. 
     
     
         6 . The ingestible medical capsule of  claim 1 , wherein the fixed anatomical feature of the subject is selected from at least one of: (i) a face, (ii) cheek, (iii) chin, (iv) tooth, (v) tongue, and (vi) mouth of the subject. 
     
     
         7 . The ingestible medical capsule of  claim 4 , wherein the anchor is configured to expand after dissociating from the capsule body. 
     
     
         8 . The ingestible medical capsule of  claim 1 , wherein the anchor is configured to anchor on a pyloric valve of the subject. 
     
     
         9 . The ingestible medical capsule of  claim 1 , wherein the anchor is configured to stop anchoring and to pass through the gastrointestinal tract of the subject after an interval of time has passed, wherein the interval of time is at least 24 hours. 
     
     
         10 . The ingestible medical capsule of  claim 1 , further comprising a spool housed within the capsule body, wherein the strand is initially wound around the spool, and wherein the capsule body is configured to track an unwinding of the strand from the spool. 
     
     
         11 . An ingestible medical capsule comprising:
 a spool;   a strand configured to unspool from the spool as the ingestible medical capsule travels through a gastrointestinal tract of a subject;   a detector configured to measure a length of the strand that unspools from the spool; and   a transmitter configured to communicate information about the length of the strand that unspools from the spool to a user external to the subject.   
     
     
         12 . The ingestible medical capsule of  claim 11 , wherein the spool is configured to revolve as the strand unspools from the spool. 
     
     
         13 . The ingestible medical capsule of  claim 12 , wherein the detector comprises:
 a magnet coupled to the spool; and   a Hall sensor configured to sense a change in a magnetic field produced by the magnet as the spool revolves.   
     
     
         14 . The ingestible medical capsule of  claim 13 , further comprising a controller electronically coupled to the Hall sensor, the controller being configured to count revolutions of the spool based on data received from the Hall sensor. 
     
     
         15 . The ingestible medical capsule of  claim 14 , further comprising a printed circuit board configured to electronically couple to the Hall sensor, the controller, the transmitter, and a power source. 
     
     
         16 . A method of localizing an ingestible medical capsule within a gastrointestinal tract of a subject, the method comprising:
 coupling a capsule body of the ingestible medical capsule to an anchor via a strand; and   measuring a linear distance between the capsule body and the anchor to determine a distance traveled by the capsule body.   
     
     
         17 . The method of  claim 16 , further comprising associating the anchor with the capsule body and coating the anchor and the capsule body with an enteric coating, wherein the enteric coating is configured to dissolve in the gastrointestinal tract of the subject, thereby causing the anchor to dissociate from the capsule body. 
     
     
         18 . The method of  claim 17 , wherein the anchor is selectively configured not to pass through a pyloric valve of the subject. 
     
     
         19 . The method of  claim 16 , further comprising spooling the strand around a spool and disposing the spool within a housing of the capsule body. 
     
     
         20 . The method of  claim 19 , wherein the measuring the linear distance between the capsule body and the anchor to determine the distance traveled by the capsule body comprises detecting a number of revolutions of the spool as the strand unspools from the spool.